Tubing hangers support tubing for wellheads in a number of applications. In general, most tubing hangers land in a tubing spool of the wellhead and support the weight of tubing that extends down the wellbore from the wellhead. One particular example of a tubing hanger is Weatherford's breech-lock tubing hanger system. This system has a false bowl and a hanger mandrel that land together in a tubing spool. Anchor screws retain the false bowl, while the hanger mandrel can be disengaged from the false bowl by lifting the mandrel in the false bowl with a landing joint and rotating the mandrel a quarter turn. In this orientation, the mandrel can be passed through the false bowl and can be run downhole. The mandrel can be reengaged in the false bowl with a reverse of these steps for placing tubing in tension.
Tubing hangers are also used for artificial lift systems. For example, a jack pump, a progressive cavity pump unit, or other device for an artificial lift system rotates or reciprocates a rod at a producing well. The rod operates downhole components of the artificial lift system to produce fluids from the wellbore. Because the moving rod passes through the wellhead and through tubing, the movement of the rod can cause excessive wear on internal portions of the tubing during operation. Additionally, the wellbore's deviation and the constituents of the produced fluids can increase the wear of the tubing. Eventually, the unevenly worn tubing can cause equipment failures so that it must be removed and replaced.
Tubing rotators are a type of tubing hanger that install on wellheads to deal with wear on the tubing by moving rods. Tubing swivels and tubing anchor catcher swivels have also been used in conjunction with tubing rotators. In general, the tubing rotator rotates the tubing within the wellbore so wear from the reciprocating or rotating rod can be more evenly distributed around the inside of the tubing. The rotation can also inhibit or reduce the buildup of paraffin or wax in the tubing.
Commercial examples of tubing rotators include the Rodec Tubing Rotator Systems available from R&M Energy Systems of Willis, Tex. Commercial examples of prior art tubing swivels include the Rodec Slimeline Tubing Swivel and Rodec AC Anchor Catcher Swivel available from R&M Energy Systems of Willis, Tex. Examples of some prior art tubing rotators and swivels are disclosed in U.S. Pat. Nos. 2,599,039; 2,471,198; 2,595,434; 2,630,181; 5,139,090; 5,327,975; and 5,427,178; and 6,834,717.
Attempts in the prior art to put tubing to be rotated under tension while using a tubing rotator have focused on aspects of the tubing anchor or swivel as disclosed in U.S. Pat. Nos. 5,139,090; 5,327,975; and 6,834,717, for example. Yet, there are limitations to current methods of setting tubing to be rotated by a “rotating tubing hanger” in tension while a blowout preventer (BOP) is installed on the well for complete well control. For example, when a rotating tubing hanger is to be used, operators run a tubing anchor in-the-hole on the bottom of the tubing string. The tubing is then spaced out to accommodate the rotating tubing hanger assembly, and operators set the anchor. With the anchor set, the tubing is stretched above the BOP (when applicable), which allows the rotating tubing hanger assembly to be installed on the tubing string. Once installed, the entire string is lowered through the BOP and landed in the wellhead. Performing these steps can be limited by the amount of stretch that can be applied to the tubing string so that this procedure may not work with some implementations.
Although existing tubing rotators and systems may be effective, what is needed is a way to rotate tubing that allows operators to pull tension on the tubing to be rotated during operation in a straightforward manner, especially when a blowout preventer (BOP) is installed on the well.